| Arin Yaprak Limited | Transport & logistics | 2023 |
| Arinmill Limited | Households | 1984 |
| Ariston Alloys Limited | | 1949 |
| ARK Consultancy Solutions Ltd | Professional & scientific | 2015 |
| ARK Vets Limited | Professional & scientific | 2006 |
| Arkology Ltd | Wholesale & retail | 2025 |
| Arkq Limited | Manufacturing | 2005 |
| Armadillo Safeguards Limited | Construction | 1980 |
| Armyn Properties Limited | Real estate | 2005 |
| Arnots Limited | Construction | 2003 |
| ARPHEM2 Limited | Health & social care | 2015 |
| Arranlee Enterprises Limited | Professional & scientific | 2000 |
| Arrowdell Limited | Construction | 1980 |
| Art Estates Limited | Real estate | 2009 |
| Art of Thought Psychological Practice Ltd | Health & social care | 2020 |
| Arthur Architects Limited | Professional & scientific | 2001 |
| Arthur Wait Limited | Construction | 1963 |
| Artmax Ltd | Construction | 2010 |
| Artro Studio Limited | Manufacturing | 2002 |
| Arts of Steel Limited | Manufacturing | 2004 |
| Arunasai Associates Limited | Information & communication | 2001 |
| Arundale (Kingston) Residents Association Limited | Households | 1978 |
| AS Borderless Trade Group Ltd | Wholesale & retail | 2026 |
| AS Partnership Ltd | Professional & scientific | 1999 |
| ASA Limited | Information & communication | 2007 |
| Ascot Data Services Limited | Administrative & support | 1989 |
| Ascot Homes Limited | Construction | 2007 |
| ASF Computer Technology Ltd. | Information & communication | 1998 |
| Ashbridge Building & Maintenance Services Ltd | Construction | 1997 |
| Ashcroft House Residents Association Limited | Households | 2001 |
| Ashferns Limited | Professional & scientific | 1997 |
| Ashford Parish Bricklayers Ltd | Construction | 2024 |
| Ashley Flooring Limited | Wholesale & retail | 2003 |
| Ashley Forms Limited | Manufacturing | 1992 |
| Ashlux Property Ltd | Real estate | 2002 |
| Ashplan Limited | Households | 1981 |
| Ashtead Fireplaces Limited | Construction | 2003 |
| Ashtead Investment Limited | Real estate | 2005 |
| Ashtead Podiatry Limited | Health & social care | 2007 |
| Ashton Lodge of Sunbury Ltd | Health & social care | 2012 |
| Ashton Manor Care Home Ltd | Health & social care | 2006 |
| Ashurst Developments Limited | Real estate | 1996 |
| Ashvale Sawmills Holdings Ltd. | Administrative & support | 2000 |
| Ashwood Park Residents Association (Woking) Limited | Households | 1991 |
| ASK Aviation Services Limited | Other services | 2007 |
| ASK C2 Luxury Concierge Club Ltd | Other services | 2018 |
| Askut Leathers and Textiles (U.K.) Limited | | 1987 |
| ASM Cars Limited | Wholesale & retail | 2004 |
| Asmi Consultants Limited | Professional & scientific | 2001 |
| ASP Tech Solution Ltd | Information & communication | 2024 |
| Aspectations Limited | Administrative & support | 2010 |
| Aspenglade Limited | Financial services | 1991 |
| Aspex Furniture Limited | Real estate | 1996 |
| Aspirational Travel Limited | Administrative & support | 2006 |
| Aspire Glow Limited | Health & social care | 2025 |
| Assure Management Limited | Administrative & support | 1999 |
| Astronic Limited | Construction | 1999 |
| Astruo Search Ltd | Professional & scientific | 2024 |
| Atalanta Limited | Other services | 2008 |
| ATC Computer Services Limited | Information & communication | 2005 |
| Athaedes Ltd | Real estate | 2021 |
| Atheray Organisation Limited | Education | 2003 |
| Athica Limited | Financial services | 2016 |
| Atiase Rehabilitation Care Limited | Health & social care | 2020 |
| Atkinsréalis Investments UK Limited | Administrative & support | 2004 |
| Atkinsréalis Kins Holdings Limited | Extraterritorial | 1961 |
| Atkinsréalis UK Limited | Professional & scientific | 1961 |
| Atlantic Training and Development Limited | Administrative & support | 2007 |
| Atlanticus Limited | Information & communication | 1997 |
| Atsb Property Ltd | Real estate | 2022 |
| Attic Conversions (Sales) Limited | Extraterritorial | 1997 |
| Attic Conversions Limited | Construction | 1980 |
| Attract Revenue Ltd | Information & communication | 2018 |
| ATW Consulting Limited | Information & communication | 2002 |
| Atwood Construction Limited | | 1988 |
| Aubrey's Auctioneers Limited | Other services | 2023 |
| Audio Reunited Limited | Administrative & support | 2006 |
| Audiovision Retail Ltd. | Wholesale & retail | 2001 |
| Audley Binswood Limited | Real estate | 2007 |
| Audley Binswood Management Limited | Real estate | 2012 |
| Audley Care Ltd | Health & social care | 2005 |
| Audley Care White Horse Ltd | Health & social care | 2008 |
| Audley Chalfont Limited | Real estate | 2012 |
| Audley Coopers Hill Limited | Real estate | 2016 |
| Audley Coopers Hill Management Limited | Real estate | 2016 |
| Audley Court Limited | Real estate | 2004 |
| Audley Court Management Limited | Real estate | 2005 |
| Audley Dormant Co Limited | Real estate | 2016 |
| Audley Ellerslie Limited | Real estate | 2012 |
| Audley Ellerslie Management Limited | Real estate | 2015 |
| Audley Financial Services Limited | Financial services | 2016 |
| Audley Flete Limited | Real estate | 2007 |
| Audley Flete Management Limited | Real estate | 2004 |
| Audley Group Developments 2 Ltd | Real estate | 2017 |
| Audley Homewood Limited | Real estate | 2017 |
| Audley Inglewood Limited | Real estate | 2005 |
| Audley Inglewood Management Limited | Real estate | 2007 |
| Audley Investments NO 3 Limited | Other services | 2019 |
| Audley Investments NO 4 Limited | Other services | 2019 |
| Audley Investments NO 5 Limited | Households | 2023 |